Process for the treatment of fabrics



some serious dis advantages.

United States Patent PROCESS FOR THE TREATMENT OF FABRICS James E.Pritchard, Barflesville, 0kla., assignor to Phillips Petroleum Company,a corporation of'Delaware No Drawing. Application Marchfi, 1952, SerialNo. 274,660

9' Claims. (Cl. 117-62) pared from pyridine derivatives containing atleast one vinyl group.

Fabrics serve many irnportant'uses but they also have .Among some of:the-problems encountered are their lack of resistance to penetration byWater, their failure to resist fading when exposed to gases containingoxides of nitrogen, infiammability, etc. Various attempts havebeen'rnadeto solvetheseproblems but so far they all'leave something tobe desired.

By the various aspects of this inventionone or more of the followingobjects will beobtained.

An object of this invention is'to provide a new process for thetreatrnent of fabrics. A further object ofthis invention is theproduction of fabrics having desirable properties. Afurther object ofthis inventionis a-process of treatment of fabrics in which theWaterrepellencyiof the fabrics is increased. A furtherobject of thisinvention is a process of treatment of-fabrics-in which resistance togas fading of the fabrics is increased. A further object of thisinvention is to provide-fabricshaving increased water :repellencyandresistance to gas fading. A-further :ob-

ject is to provide fabrics which are non-inflammable. Other objects andadvantages .of this invention .Will becomeapparent to one skilled-in theart-upon reading this disclosure.

In accordance with this invention the fabric to be treated isimpregnated with a polymer of a pyridine derivative containingatleastone vinyl group. This treatment is preferably carried out byimpregnating the fabric with an aqueous acid solution of the polymer,and, if desired, subjecting the resulting fabric to an additionaltreatment with an aqueous solutiomof abasic material so as to convertthepyridinium salt originally formed to the free polymeric base,removing the excess baseby washing with water and finally dryingtheresultingimpregnated fabric. By impregnation -l mean'to include caseswhere each fiber is treated butnot necessarily where all the intersticesof the fabric are filled.

Various fabrics can be treated according to a process of this invention.Where water repellency is desired, fabrics, such as cotton, linen, wool,silk, and rayon, preferably of close Weave are used. The problem ofgasfading is particularly important when dealing with cellulose acetatefabrics, said fabrics being especially subject to vfading when exposedto gases such as are formed by the combustion of fuel gases,illuminating gases, and the like. The oxides of nitrogen, such as N20,NO, N02,.N2O3, and N205 are known to have a deleterious effect on dyedcellulose acetate fabrics, various shades of blue anthraquinone dyesbeing the most susceptible-to gas fading.

In this process the fabric to be treated is immersedin the impregnatingsolution until it is saturated. Insome instances no further treatment,beyond removing and preferably methyl and ethyl groups.

. above,

group in the range drying, is necessary, since the fabric at this stagehas the desirable properties. In other cases, further treatment includesthe application of a basic material, such as alkali metal hydrox de,carbonate or bicarbonate, rinsing to removeany excess of basic material,and drying.

It is not necessary and usually not desirableto dry the fabric beforeimmersing it in the basic solution. However, it may be desirable toremove some of the Water in order that substantially all the polymericmaterial, which is in the form of a pyridinium salt, will adhere to thetextile during treatment with the basic solution. This alkaline treatingsolution, which converts the pyridinium salt to the free polymeric base,should be of such concentration that it will not harm the fabric.Preferably, a concentration not greater than 1 per cent by weight isemployed, or, expressed in other terms, a 0.01 N to 0.25 N solution isemployed. Only the very dilute solutions should be employed on materialssuch as wool while stronger concentrations can be employed with moreresistant textiles such as cotton.

Compounds used for the preparation of the polymers are the monoanddivinylpyridines, with the vinyl groups being present in any of theseveral positions in the pyridine nucleus. Alkyl groups can be presentonthe'ring or on the OC-Cal'bOft of the Vinyl group, but the number ofcarbon atoms in the combined alkyl groups shouldgenerallynot be greaterthan 12. These alkyl groups are These .compounds have the structuralformula where R is selected from the group consisting of hydrogen,alkyl, vinyl, and alpha-methylvinyl groups; at least one and notmorethan twoof said groupsbeing vinyl or alpha-methylvinyl; and thetotal number of carbon atoms in thealkylgroups beingnot greater than 12.Examples of such compounds are Z-vinylpyridine; 2,5-diviny1- pyridine;Z-methyl-S-vinylpyridine; 2,3,4,-trimethyl-5-vinylpyridine; 3,4,5,6-tetramethyl-Z-Vinylpyridine; 3-ethy1- 5- vinylpyridine;2,6-diethyl-4-vinylpyridine; 2-isopropy1-4- nonyl-S-vinylpyridine;2-methyl-5-undecyl-3-vinylpyridine; 3-dodecyl-4,S-divinylpyridine;2,4-dimethyl-5,6-dipentyl-3 -vinylpyridine; Z-decyl-S a-methylvinyl)pyridine;

3,5-di(a-methylvinyDpyridine; and the like.

The polymeric starting materials employed range from rubbery to solidresinous polymers. In addition, copolymers of conjugated diolefins withthese pyridine derivatives can beemployed, and in fact it has been foundthat the copolymer gives agreater amountof water repellency.

;For waterrepellency i prefer to use a copolymer of from 15 to '75 partsby weight of the conjugated diolefin and from to 25 parts by weight ofthe pyridine derivative containing at least one vinyl group. A specificexample of a copolymer which imparts excellent water repellencycharacteristics to a fabric is a 50/ 50 butadiene/Z-methyl-5-vinylpyridine copolymer, either in the form of the free polymericbaseor the correspondingpyridinium salt.

The conjugated diolefin component in the copolymer imparts low watersolubility to the product and gives greater flexibility .While thepyridine derivative component imparts low oil solubility to the product.However, .homopolymers of the pyridine derivatives mentionedparticularly poly-.Z-vinylpyridine and poly-2- methyl-S-vinylpyridine,can be employed. These homo- .polymers are preferred for improving theresistance to gas fading of the fabrics. However, good resistance to gasfading is obtalned where copolymers prepared from conjugated diolefinsin the range from 0 to 15 parts by Weight and pyridine derivativescontaining at least one vinyl from to 85 parts by weight are employed.

Conjugated diolefins which containfrom4 to 6 carbon Monomers "parts byweight 100 Water do 180 Soap flakes do 5 S208 do 0.3 Mercaptan blend 1do 0.4 Temperature C 50 A blend of tertiary C12. C14. and C aliphaticmercaptans 'in aratio of 3 1 z 1 parts by weight.

The 75/25 and 50/50 butadiene/Z-methyl-S-vinylpyridine copolymers wereshort-stopped with 0.1 per cent hydro- 'quinone and stabilized with 2per cent phenyl-beta-naphthylamine. They were coagulated with acid andbrine and washed with base to obtain soap-free polymer containing freepyridine nitrogen. The 2-methyl-5-vinylpyridine homopolymers wereprecipitated from acidified latex by addition of base. They contained noshortstop or antioxidant and were obtained as soap-free polymers afterwashin with base and water.

Solutions which are employed are prepared by dissolving the polymer inan aqueous solution of an acid. the

' acid solution of the desired concentration generally being preparedfirst, after which the olymer is added, said polymer going into solutionby agitation. Sometimes, a more concentrated solution of acid can beemployed than is used in the impregnating solution and the solutiondiluted to the desired concentration after the polymer is dissolved. lninstances where a liquid acid, such as acetic acid, is used. a polymercan be treated with the glacial acid and the mixture then diluted priorto use. Re ardless of the acid concentration employed, the polymerdissolves with the formation of a pvridinium salt. Solvation of theresin can be obtained when only one-fourth of the stoichiometricequivalent of acid is used but lar er amounts of acid. even u to severalchemical eouivalents can be used conveniently. The solution should besufficiently dilute with respect to the nolvmer that uniform imprenation of the fabric can be facilitated. Solutions of polymer ran in inconcentration from 0.1 to by weight are fre uently employed.

, Acids which are a plicab e must possess sufiicient water solubility inorder that solutions of the desired concentration can be repared. Withsaturated and unsaturated aliphatic monobasic and dibasic or anic acidscan be em- ,ployed as we l as mineral acids. Examples of acids which areapplicable include formic; acetic. propionic. butvric, oxalic. malrmic.maleic. succinic. glutaric, glvcolic. chloroacetic, dichloroace ic.trichlor acetic. hydrochloric. sulfuric. nitric. and phosphoric. Theacidity of the impregnating solution is regulated so that the f bricswill .not be harmed during the treating process. The pH is preferabl inthe ran e from 2 to 6.

In another embodiment of my invention, the impregnating agent may beemployed in therform of a latex. In this treatment, the fabric isimmersed in the latex, squeezed to remove excess latex and then ovendried. Following this drying, the soap and other soluble materials areremoved by washing after which the material is a ain dried.

The amount of treating agent used is dependent upon the type of fabric,the weave, and the ultimate use. The

amount is generally in the range between 0.04 and 5 pounds of the freepolymeric base per 100 pounds of correspondingly increased.

The materials of this invention have numerous advancording to TestMethod 4245.

tages. They are readily applied tothe fabric in the form of diluteaqueous solutions and require only ordinary drying with no special heattreatment to insure a permanent finish. They are resistant to launderingand dry cleaning. The solutions employed impregnate the fibers insteadof forming a coating on the surface of the material and are therefore tobe preferred over coatings which have a tendency to flake off or crackand which are therefore less permanent. Furthermore, where the fabric isimpregnated rather than coated the natural hand of the fabric is notchanged.

In the following tests, the water repellency of selected fabrics hasbeen evaluated by two of the test methods described in the 1950Technical Manual and Year Book of the American Association of TextileChemists and Colorists. The first method was Tentative Test Method42-45, Resistance to Penetration of Water by Impact. According to thismethod, 500 cc. of water from a standard spray head impinges upon thefabric stretched over a piece of blotting paper and held 24 inches belowthe spray head at an angle of 45 with the water stream.

Standard Test Method 22-41, Resistance to Water Spray;

In this method the test specimen, stretched tightly in a sixinchembroidery hoop, is held at a 45 degree angle six inches below astandard spray head. After pouring 250 cc. of water through the sprayhead the fabric is rated with respect to its water repellency. Ratingsare made on a scale of zero to 100 where zero represents completewetting of upper and lower surfaces and 100 represents complete absenceof wetting. A rating of 50 indicates complete wetting of upper fabricsurface, 70 signifies partial wetting of upper surface, 80 representspartial wet ting to give a sharp spray-head pattern, and indicatesslight random wetting of upper surface.

Example I Uniform samples of cotton ticking, rayon, and wool gabardinewhich had been laundered to remove sizing were impregnated with aqueousactic acid solutions of a 50/50 butadiene/Z-methyl-S-Vinylpyridinecopolymer and poly-2-rnethyl-5-vinylpyridine. .The solutions wereprepared in the following manner:

1. A 50/50 butadiene/Z-methyl-5-vinylpyridine copolymer was dissolved ina 15 per cent aqueous solution of acetic acid in the proportion of 1.5grams of copolymer per cc. of solution.

2. A portion of solution No. 1 was diluted with twice its volume ofwater to give a solution containing 0.5 gram of copolymer per 100 cc.

3. Poly-2-methyl-5-vinylpyridine was dissolved in a 15 per cent aqueoussolution of acetic acid in the proportion of 1.5 grams polymer per 100cc. of solution.

In each case the sample of fabric to be treated was dipped into theimpregnating solution, squeezed-to remove excess solution, dried, andsome of the samples were then immersed in a 0.05 N sodium hydroxidesolu-.

in various ways and then tested for water repellency.

Details of treatment of each sample follow.

a. Water-repellency test as described above, measured by increase inweight of blotting paper.

b. Sample from (a) was dried, immersed in carbon tetrachloride for 10minutes, removed and carbon tetrachloride evaporated, md thewater-repellency test repeated.

0. Sample from '(b) was laundered at 100 F. for 10 minutes in a sodiumsoap solution containing 5 grams of 88 per cent neutralized stearic acidper liter of water, rinsed, dried, and the water-repellency test made asbefore.

d. Sample from (c) was treated for 30 minutes with a F. soap solutionprepared as in '(c), rinsed, dried, and tested for water repellency.

e. Sample from (d) was dried, immersed in carbon tetrachloride, for onehour, removed and carbon tetra- The following table presents results'oftests madeac- 4 OZ. COTTON TIGKING Impact Penetration, gramsImpregnsting Solution No. z i 5 a b c d e 0. 6 0. 6 0. 7 g 0. 4 1. 52.1 1. 7 s. 2 3 26 NonetUntreatedsample) 36. 5

8 OZ. RAYON GABARDI'NE Example 11 it) Quagrtrty has of Fabric in solu hPenetra- Test tion Pounds Rum? Fabric 0 26 9 oz. Cotton Twill 1 9 0024oz; .Cotton'licking; 3 i 58 g so 1002. Cotton Duck 2 no 100 JO 0 19 708' oz; Rayon Gabardine 0. 6 0 80 l. 8 O. 1 80 6 02. Wool Flannel g 9 8:Z 0 9. 4 10 oz. Wool Gabardine 0.7 O 90 1. 7 0 90 It is noted that spraytest ratings of 80 to 100 were obtained for the treated fabrics. Thesevalues indicate that the fabrics and yarns were highly water repellent.Ratings inthis test are dependent upon the characteristics of the fibersand not upon fabric construction. Ratings in the impact penetration testare dependent to a great xtenton'the' type of weave.

Example III Apiece of cotton ticking was immersed in a /25butadiene/Z-methyl-5-vinyipyridine copolymer latex containing 4 per centpolymer by weight, squeezed dry and 7 0 then dried in an air oven at 60C. The cloth was then washed to remove soap and other soluble materialsand again dried in an air oven at 60 C. For this material thepenetration value was 1.0 gram. Following immersion. in carbontetrachloride for 30 minutes the penetration value was again determinedand found to be 2.3 grams.

Similar tests were performed with cotton ticking using a polybutadienelatex diluted to contain approximately 4 per cent polymer by weight. Theoriginal treated material had a penetration value of 2.4 grams.Treatment with carbon tetrachloride for 30 minutes producedmaterial-which showed no water repcllency, i. e., the arnount of. waterwas in excess of that which could be measured accurately on the blotter.

The determination ofthe resistance to gas fading was made in twodifferent ways, treatment with the gas given off from nitric acid, andalso a regular test as specified by the American Association of TextileChemists and Colorists. These two methods are discussed in connecionwith the specific example in which they are use Example IV Samples ofbright blue acetate rayon were treated to remove sizing, materials forinhibiting. fading, etc.,. by immersing them in carbon tetrachloride for10 minutes, evaporating the solvent, and then laundering them' at F. for10 minutes in av sodium. soap solution. con taining 5 grams of 88 percent. neutralized stearic acid per liter of water. One sample wasreserved as a' control and the rest were impregnated with aqueousacetic: acid solutions of poly-Zunethyl-Svinylpyridine of variableconcentrations. The polymeric starting material was a white powder.Stoichiometric quantities. of acetic acid and the polymer were employed,that. is, an. amount of acetic acid equivalent to the basic groups inthe polymer. After the polymer dissolved in the acid-to-formthepyridinum salt, difierent portions of this solution were diluted to givesolutions conta-iningthe following concentrations of polymer acetate:

(1) 0.1 weight per cent (2) 0.5 weight per cent ('3) 1.0 weight percent(4) 2.0 weight per cent One sample of cloth was immersed in eachimpregnating' solution, squeezed to. remove: excesssolution, dried, andthen immersed in a 0.0.5 N sodium hydroxide solution. The samples werethen rinsed to remove excess sodium hydroxide and dried. The cloth aftertreatment had the same feel or hand as the untreated material.

Tests for resistance to gas fading were carried out in an aircirculating oven. Test specimens were exposed to an atmospherecontaining approximately 3 volume per cent N235 (vapors from ananhydrous HNOs bottle) for a 48-hour period at a temperature of F. Theuntreated sample changed in color from blue to-purple. Samplesimpregnated with solutions containing 0;5', 1.0;

g and 2.0 per cent polymer acetate, respectively, showed a verynoticeable improvement (resistance to fading). Some improvement wasnoted when solution 1, containing 0.1 per cent polymer acetate, wasused.

Additional samples of the acetate rayon used in previous tests, andtreated to remove sizing, etc., were weighed and immersed in treatingsolutions 1' to 4' hereinabove described, squeezed to remove excesssolution, and weighed. Calculations showed that the polymer was appliedat the following rates using the different treating solutions:

(1) 0.04 pound per 100 pounds of fabric (2) 0.20 pound per 100 pounds offabric (3) 0141 pound per 100 pounds of fabric (4) 0.82 pound per 100pounds of fabric Example V The procedure of Example IV was employed forpreparing solutions containing 0.1, 0.5, 1.0, 2.0, and 8.0 weight percent poly-2-methyl-5-vinylpyridinium acetate and for using thesesolutions to impregnate test specimens of blue acetate rayon from whichsizing and fading inhibitors had been previously removed. The sampleswere exposed to a mixture of nitrogen oxides, N203, N02, and NO,produced by the action'of sulfuric acid on sodium nitrite. All thetreated samples showed resistance to fading after being heated in theatmosphere containing nitrogen oxides for 16 hours at 140 F. Anuntreatedspecimen changed to a purple color.

Example VI Samples of blue acetate rayon from which sizing and fadinginhibitors had been removed were treated in various ways and thenexposed for two hours at a temperature of 200 F. to an atmospherecontaining vapors from commercial concentrated nitric acid. The methodof treating the test specimens and the results obtained are given below.One untreated sample was. reserved as a control.

(1 Sample treated with an 8 weight per cent aqueous solution ofpoly-2-methvl-5-vinylpyridinium acetate, dried, and then washed withsodium hydroxide solution, rinsed. and dried. The sample remainedsubstantially unfaded when exposed to an atmosphere containing nitricacid vapors.

(2) Sample prepared as in 1) was laundered for 10 mmutes at 100 F. in asodium soap solution containing grams of 88 percent neutralized stearicacid per liter of water. The fabric showed good resistance to fadingwhen exposed to an atmosphere containing nitric acid vapors.

(3) Sample prepared as in (1) was dry cleaned by immersing It in carbontertachloride for minutes. No fading was observed after exposure tonitric acid vapors.

(4) Sample treated with an 8 weight per cent aqueous solution oftriethylenetetramine, dried. rinsed. and dried. No resistance to fadingwas accomplished. The sample had the same appearance as the untreatedfabric, the blue color changing to reddish purple.

(5) Sample treated with an 8 weight per cent aqueous solution oftriethvlenetetramine and dried. Considerable resistance to fading wasobserved. (It is known that polyamines of this type have been used toeffect resistance to gas fading but the finish is not permanent.) Thetreating agent is readily washed out upon laundermg as shown in test(4). i

(6) Sample treated with an 8 weight per cent aqueous solution ofpoly-2-vinylpyridinium acetate, dried. washed with sodium hvdroxidesolution. rinsed. and dried. Some resistance to fading was observedafter exposure to an atmosphere containing nitric acid vapors.

(7) Sample from which sizing, inhibitors for fading, etc., had beenremoved, but otherwise untreated, was exposed to an atmospherecontaining nitric acid vapors. The blue color changed to reddish purple.

Example VII The procedure of Example TV was employed for preparingsolutions containing 1.0, 2.0, and 8.0 wei ht percentpoly-2-methyl-S-vinylpyridinium acetate and for using these solutions toimpregnate test specimens of li ht blue acetate rayon. One end of eachspecimen was impregnated with the test solution and each entire specimenwas base washed.

The acetate ravon employed for making the tests was in the form ofribbon 2% inches wide. A standard of fading was available forcomparison. This specimen was a sample of acetate rayon dved to a shadewhich would correspond to the shade obtained after exposing theuntreated test specimens for six months to air containing an averagecontent of nitro en oxides, such as would be present in the air as aresult of burning gas. A descri tion of the standard of fading, theribbon employed for test specimens, and the procedure used fordetermining resistance to gas fading is found in the 1950 TechnicalManual and Year Book of the American Association of Textile Chemists andColorists, volume XXVI, pp. 88-90.

Test specimens which had been impregnated with the poly 2 --methyl 5vinvlpyridinium acetate solutions described above and also an untreatedcontrol sample were exposed t air which had been passed through theflame of a lighted gas burner. A sample of rayon which had been treatedwith a 2.0 per cent solution of triethanolamine was also included forcomparison. (Triethanolamine is a known treating agent for acetate rayonto improve resistance to gas fading.) A temperature of 60 C. wasmaintained throughout the test. The samples were allowed to remain inthe testing chamber until the control sample showed a change of shadecorresponding to that of the standard of fading. This test period isknown as one exposure period. When making these tests, in the event thatany of the samples being tested show no fading, they are again suspendedin the testing chamber together with a fresh control. When the controlspecimen shows a change in shade corresponding to that of the standardof fading, a second exposure period is indicated. This procedure isrepeated as often as is necessary or desired to disclose the number ofexposure periods necessary to produce an appreciable alteration inshade. After each exposure period the samples are removed from thetesting chamber and compared with 8. the respective unexposed portionsof the specimens. The following method of rating is used:

No. of Rating Exposure Shade Change Periods 1 Appreciable.

1 No appreciable. Very good 2 D Earm llpnt 3.5 D

Using the above method of rating, the following results were obtainedwith the samples impregnated with the solutions hereinbefore described:

The effect obtained with triethanolamine was good, as noted above, afterone exposure period but its inhibiting activity decreased markedly uponfurther exposure in the testing chamber.

Example VIII A sample of poly-2-methyl-5-vinylpyridine was treated withone-fourth the stoichiometric equivalent of glacial acetic acid andwater was then added to give a solution containing 7.2 per centpoly-2-methyl-5-vinylpyridine by weight. This soluution was diluted withwater to give a stable, opaque dispersion containing 3.6 per cent byweight of poly-Z-methyl-S-vinylpyridine. This dispersion had a pH of5.1. A sample of light blue cellulose acetate fabric was impregnatedwith the test solution, squeezed to remove excess solution, dried in anoven at 60 C., and then exposed to air which had been passed through theflame of a lighted gas burner. Slight even fading was observed after twoexposure periods. For comparison a sample of cellulose acetate fabricwas treated in a similar manner with anraqueous solution containing 3.6per cent triethanolamine. After two exposure periods reddish spotsappeared on this sample.

The above methods of treating fabrics can be employed for simultaneouslydyeing the fabrics and rendering them resistant to gas fading. Theimpregnating material is added to the dye bath along with the acetatecolor, resulting in a single bath operation. It has been found thatfabric is impregnated with resin during dyeing if HCO3- is added slowlyto the boiling dye bath.

Example IX Another method which I have found suitable for applying thesepolymers to fabrics is to dissolve the impregnating agent in an organicsolvent and to apply it to the fabric in this manner. Using this methoda piece of cotton ticking was immersed in a 2 per cent carbontetrachloride solution of a 50/50 butadiene/2-methyl-5- vinylpyridinecopolymemr. The fabric was dried at 60 C. in an air oven.

This material had a penetration value of 0.1 gram. Following immersionin carbon tetrachloride for 30 minutes the penetration was againdetermined and found to be 2.3 grams. The untreated material had apenetration of 38 grams.

Chlorinated organic compounds can be used as solvents for polymers ofthese pyridine derivatives and copolymers prepared using the pyridinederivatives in all proportions. Alcohols, ketones, and aldehydes aresuitable Where the copolymer is prepared using a major proportion of thepyridine derivative; while hydrocarbons are suitable when the copolymeris prepared using a minor proportion of the pyridine derivative.

9 Example X Fabrics impregnated with the polymeric pyridinium phosphatesalts exhibit the desirable property of being flameproof. To demonstratethis a solution was prepared by dissolving 1.05 parts by weight ofpoly-2-vinylpyridine in 18 parts by weight of water containing 0.98 partby weight of orthophosphoric acid (H3PO4) to provide poly-2-vinylpyridinium dihydrogen phosphate. The mol ratio of pyridinenitrogen to orthophosphoric acid is 1:1.

Swatches of cotton cloth were immersed in the solution so formed andwere then air dried. Some stiffening was imparted to the cloth. Onlyhalf of each swatch was treated leaving the untreated half as a control.Controls were also prepared by immersing swatches of cotton cloth in a10 weight per cent aqueous solution of sodium phosphate and in a 10Weight per cent solution of poly-2- vinylpyridinium hydrochlorideprepared by combining poly-2-vinyl-pyridine and hydrochloric acid in amol ratio of 1:1.

In order to test these materials the untreated end of each specimen wasignited and in each case the flames propagated readily in the untreatedcloth. The hydrochloric acid salt of the polymer exhibited no flameretardant properties. Cloth treated with sodium phosphate smoldered forseveral minutes and continued to char. The cloth treated with thephosphate salt of the polymer did not support any type of combustion.

For the purpose of flameproofing, i. e. not capable of supportingcombustion, the polymeric salt is frequently applied in an amountgreater than that mentioned previously. This amount is from 1 to 15pounds per 100 pounds of fabric, preferably 2 to pounds per 100 poundsof fabric based upon the free polymeric base.

As many possible embodiments may be made of this invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. A method of treating fabrics comprising dissolving in an aqueoussolution of an acid a polymer of a pyridine derivative of the formulawhere R is selected from the group consisting of hydrogen, alkyl, vinyl,and alpha-methyl-vinyl; at least one and not more than two of saidgroups being selected from the group consisting of vinyl andalpha-methylvinyl; and the total number of carbon atoms in the alkylgroups being not greater than 12; immersing the fabric in said solution;removing and at least partially drying said fabric; immersing saidfabric in an aqueous solution of a compound selected from the groupconsisting of alkali metal hydroxides, carbonates, and bicarbonates toform the free polymer base; washing to remove any excess of the secondtreating solution; and drying the fabric so treated.

2. The method of claim 1 in which said aqueous solution contains from0.1 to per cent by weight of the polymer and the basic solution has anormality of from 0.01 N to 0.25 N.

3. A method of treating fabrics, made of fibers selected from the groupconsisting of cellulose, cellulose acetal, and protein fibers,comprising dissolving in an aqueous solution of an acid a polymer of apyridine derivative of the formula where R is selected from the groupconsisting of hydrogen, alkyl, vinyl, and alpha-methylvinyl; at leastone and not more than two of said groups being selected from the groupconsisting of vinyl and alpha-methylvinyl; and the total number ofcarbon atoms in the alkyl groups being not greater than 12; immersingthe fabric in said solution; immersing said fabric in an aqueoussolution of a compound selected from the group consisting of alkalimetal hydroxides and carbonates to form the free polymer base; washingto remove any excess of the second treating solution; and drying thefabric so treated.

4. The method of claim 3 in which the fabric is made of cotton fibers.

5. The method of claim 3 in which the fabric is made of wool fibers.

6. The method of claim 3 in which the fabric is made of celluloseacetate fibers.

7. A method of treating fabrics comprising preparing an acidic aqueoussolution of a polymer prepared by polymerizing a mixture containing acompound selected from the group consisting of conjugated diolefins andcompounds containing the CH2=C group, and a pyridine derivative of theformula where R is selected from the group consisting of hydrogen,alkyl, vinyl and alpha-methylvinyl, at least one and not more than twoof said groups being of the group consisting of vinyl andalpha-methylvinyl, and the total number of carbon atoms in the alkylgroups being not greater than 12; the weight ratio of the former to thelatter being up to 3 to 1; immersing the fabric in said solution;immersing said fabric in an aqueous solution of a compound selected fromthe group consisting of alkali metal hydroxides, carbonates andbicarbonates to form the free polymer base; washing to remove any excessof the sezond treating solution; and drying the product so treate 8. Themethod of claim 7 in which 2-methyl-5-viny1- pyridine is the pyridinederivative and butadiene is the polymerizable comonomer.

9. The method of claim 7 in which 2-viny1pyridine is i the pyridinederivative and butadiene is the polymerizable COI'HOHOIIICI'.

References Cited in the file of this patent UNITED STATES PATENTS2,402,020 Cislak et al. June 11, 1946 2,540,984 Jackson Feb. 6, 19512,561,215 Mighton July 17, 1951 2,564,726 Sauer Aug. 21, 1951 FOREIGNPATENTS 369,778 Italy Mar. 29, 1939

1. A METHOD OF TREATING FABRICS COMPRISING DISSOLVING IN AN AQUEOUSSOLUTION OF AN ACID A POLYMER OF A PYRIDINE DERIVATIVE OF THE FORMULA